1. Field of the Invention
The present invention relates to a rotary machining device and more particularly to a portable rotary machining device that may be used to machine the excess weld from welded-in valves such as breech lock gate valves.
2. Description of the Prior Art
The assembly of breech lock gate valves involves the welding in place of certain components which results in a circular peripheral weld bead, some of which extends above the flat valve body surface that surrounds an upwardly extending valve stem. The valve is constructed such that the seal is welded to the bonnet and the bonnet is welded to the body. To complete the valve assembly it is necessary to remove the excess peripheral weld bead to be flush with the flat surface. It is often necessary to perform this operation while the valve is still installed in the system and located in rather inaccessible places, especially on board ship.
Former methods utilized a carbon arc or a high speed grinder to machine flush welded-in breech lock valves. The primary disadvantages with these techniques are that the high heat content from the carbon arc often results in warpage and a grinder is time consuming and constitutes a safety hazard especially on large valves. Moreover, after using the techniques it is still often necessary to remove the valve from the system for further machining.
The present invention overcomes these disadvantages by providing a portable machining device that rapidly, effectively and with minimal safety hazard, removes the excess peripheral said from welded-in valves such as breech lock gate valves.